You already nabbed one, but yes, the Nautilus is miles ahead of the Krome (and hardly an old design, it launched in 2021. And although it's a 'cut down' version of the Kronos, I *love* the new piano interface.)
As for clicking, I don't hear 'clicking' per se either, like happyrat. However, the black keys do make a gentle sound, vs no sound on the white keys, so of course you're wondering if that's normal. Across the industry, yeah. However, I only had an 88 on display (don't even have a display atm) so of course, every key *thumped* because it was an 88 weighted key board. So I can't say for sure on the semi weighted keys.
There *is* a gentle thump on our PA5x76 display, every key, and yes the black keys are *slightly* louder. But hardly worrying. Basically, if you're playing through speakers or headphones at a comfortable level (not too loudly, for example), the click should not 'jut out' above the piano sound.
Wait until you try one of the Yamaha PSRsx keys... those black keys are a *lot* louder.
The Krome's keys are lower grade, btw.
I would suggest swapping for an 88 key if you can, because then the thump would be roughly the same between black and white keys, and thus probably less worrying?
Cheers,
Mark
*edit* oh, I see, you're saying that 2 of the black keys squeak a little louder than the others. Yes, they should take care of that or swap you another one. Or offer to swap you another board completely. No, it wouldn't bother me, but if it bothers you, yes, that absolutely should be under warranty. I've had boards with *inconsistent* key noise that were looked at under warranty (either swapping the keys or the board) from all brands, though.
www.youtube.com/MarkWilburnTLM/Videos
DX7, CLP300, PSR60, Roland E20, CVP309, PSRS970, Fender Strat, Ibanez SA262, Yamaha CG131, Fujiyama FC390, TUC-Kitty